Improve performance of admin/conference/*/registrations

* Add some caching
* Reduce query count, including N+1s on questions & roles

app/controllers/admin/registrations_controller.rb

@@ -8,13 +8,17 @@ module Admin
 
     def index
       authorize! :show, Registration.new(conference_id: @conference.id)
-      @pdf_filename = "#{@conference.title}.pdf"
-      @registrations = @conference.registrations.includes(:user).order('registrations.created_at ASC')
-      @attended = @conference.registrations.where('attended = ?', true).count
+      @registrations = @conference.registrations.eager_load(
+        :qanswers, user: :roles
+      ).order('registrations.created_at ASC').to_a
+      @attended = @registrations.count(&:attended)
+      @questions = @conference.questions.to_a
 
       @registration_distribution = @conference.registration_distribution
       @affiliation_distribution = @conference.affiliation_distribution
       @code_of_conduct = @conference.code_of_conduct.present?
+
+      @pdf_filename = "#{@conference.title}.pdf"
     end
 
     def edit; end

app/views/admin/registrations/_questions.html.haml

@@ -1,9 +1,5 @@
-- @conference.questions.each do |q|
-
-  %b Q:
-  = q.title
-
-  %b A:
-  - registration.qanswers.where(question_id: q.id).each do |qa|
-    = qa.answer.title
-  %br
+- cache [:admin, @conference, registration.qanswers] do
+  %dl
+    - registration.qanswers.each do |qa|
+      %dt= qa.question.title
+      %dd= qa.answer.title

app/views/admin/registrations/index.html.haml

@@ -32,18 +32,19 @@
                 %abbr{ title: 'Code of Conduct' } CoC
             %th Arrival
             %th Departure
-            - if @conference.questions.any?
+            - if @questions.any?
               %th Questions
             %th Actions
         %tbody
           - @registrations.each_with_index do |registration, index|
+            - cache [:admin, registration, registration.user] do
               %tr
                 %td
                   = registration.id
                 %td
                   = registration.name.present? ? registration.name : registration.username
-                %br
-                - registration.user.roles.where(resource: @conference).each do |role|
+                  %b
+                  - registration.user.roles.select{|r| r.resource == @conference}.each do |role|
                     %span.label.label-info
                       = role.name.titleize
                 %td
@@ -65,13 +66,18 @@
                     = registration.departure.strftime('%d %b %H:%M')
                   - else
                     n/a
-              -if @conference.questions.any?
+                -if @questions.any?
                   %td
                     = link_to 'Questions','#', class: 'btn btn-success question-btn', 'data-id' => index, 'data-name' => registration.name
                 %td{ 'data-order' => registration.attended.to_s }
                   = check_box_tag "#{@conference.short_title}_#{registration.id}", registration.id, registration.attended,
-                  class: 'switch-checkbox',
-                  url: toggle_attendance_admin_conference_registration_path(@conference.short_title, id: registration.id)+"?attended="
+                    class: 'switch-checkbox', method: :patch,
+                    url: toggle_attendance_admin_conference_registration_path(@conference.short_title, id: registration.id)+"?attended=",
+                    data: { size: 'small',
+                            on_color: 'success',
+                            off_color: 'warning',
+                            on_text: 'Present',
+                            off_text: 'Absent' }
                   .btn-group
                     = link_to 'Edit', edit_admin_conference_registration_path(@conference.short_title, id: registration),
                     method: :get, class: 'btn btn-primary'

app/views/admin/registrations/index.pdf.prawn

@@ -23,10 +23,8 @@ prawn_document(force_download: true, filename: @pdf_filename, page_layout: :land
     row << registration.departure.to_s || ''
 
     @conference.questions.each do |question|
-      qa = registration.qanswers.find_by(question: question)
-      answer = ( qa ? qa.answer.title : '' )
-
-      row << answer
+      qa = registration.qanswers.find{|qa| qa.question_id == question.id }
+      row << ( qa ? qa.answer.title : '' )
     end
 
     table_array << row

app/views/admin/registrations/index.xlsx.axlsx

@@ -5,7 +5,7 @@ wb.add_worksheet(name: 'registrations') do |sheet|
   bold_style = wb.styles.add_style(b: true)
   row = ['Attended', 'Name', 'Nickname', 'Affilιation', 'Email', 'Arrival', 'Departure']
 
-  @conference.questions.each do |question|
+  @conference.questions.sort_by(&:id).each do |question|
     row << question.title
   end
 
@@ -21,13 +21,10 @@ wb.add_worksheet(name: 'registrations') do |sheet|
     row << registration.arrival.to_s
     row << registration.departure.to_s
     @conference.questions.each do |question|
-      qa = registration.qanswers.find_by(question: question)
-      answer = ( qa ? qa.answer.title : '' )
-
-      row << answer
+      current_qa = registration.qanswers.find{ |qa| qa.question_id == question.id }
+      row << ( current_qa ? current_qa.answer.title : '' )
     end
 
     sheet.add_row row
   end
 end
-